With the rapid development of mobile Internet, the software and hardware technologies of smart phones have been rapidly improved, and the price has also developed towards more and more civilians, making the development of smart phones more diversified in China. It is also becoming more and more comprehensive and plays an extremely important role in people's intelligent life.
As an important part of smart phones, improving the production pass rate of the touch screen and the production quality of the mobile phone is a very important part of the popularization of the mobile phone. The Mark center point of the unqualified touch screen is quite different from the Circle center, which causes a large exposure problem on the front of the product. Traditional touch screen Mark detection adopts semi-automatic measurement method with manual participation. Due to the instability of manual placement, the detection station changes too much, which leads to inaccurate detection and low efficiency, and the degree of automation and stability are not high enough.
FIG. 3 is a schematic diagram of the touch screen to be detected. There are 4 flag positions, which are Leftmark, Rightmark, Leftcircle and Rightcircle. It is necessary to detect the deviation distance between the Mark center point and the Circle center in Area A, and the deviation distance between the Mark center and the Circle center in Area B in order to judge whether the touch screen is qualified or not.